mock-fps

A Go mock server simulating the Form3 Faster Payments Service (FPS) API. Returns realistic JSON:API responses with async lifecycle status transitions, stand-in mode, and webhook notifications.

Quick start

task build
task run

The server starts on :8080 by default.

Configuration

Variable	Default	Description
PORT	8080	HTTP listen port
LIFECYCLE_STEP_DELAY_MS	500	Delay between status transitions
WEBHOOK_WORKERS	4	Concurrent webhook delivery workers
WEBHOOK_BUFFER_SIZE	1000	Webhook notification queue size

API overview

All endpoints are under /v1 and follow JSON:API conventions (application/vnd.api+json).

• Payments — POST/GET /v1/transaction/payments
• Submissions — POST/GET .../submissions
• Admissions — POST/GET/PATCH .../admissions
• Returns — POST/GET .../returns and .../returns/{id}/submissions
• Recalls — POST/GET .../recalls, .../submissions, .../decisions
• Reversals — POST/GET .../reversals and .../reversals/{id}/submissions
• Subscriptions — CRUD /v1/notification/subscriptions
• Health — GET /health
• Admin — GET/PUT /admin/standin (stand-in mode control)

Tasks

task build    # Build binary
task run      # Build and run
task test     # Run tests with -race
task check    # Test + clean
task clean    # Remove build artifacts

Links

Documentation	https://h3-mock-fps.statichost.page/
Source (Codeberg)	https://codeberg.org/hum3/mock-fps
Mirror (GitHub)	https://github.com/drummonds/mock-fps
Docs repo	https://codeberg.org/hum3/mock-fps-docs

License

See LICENSE.